Home Nano Research Article
PDF (22.9 MB)
Cite
EndNote(RIS) BibTeX
Collect
Submit Manuscript
Research Article | Open Access

Synthesis of monolayer tungsten nitride: Rapid optical visualization and electrical impact of grain boundaries

Qiuyun Yang1,2,§, Dehu Li1,§, Fanfan Shi1,§, Zhibin Shao3, Na Wang2, Yao Peng1, Edwin Hang Tong Teo4, Zheng Liu4 (), Hong Wang1 ()
Department of Physics, University of Science and Technology of China, Hefei 230026, China
Institute of Electrical and Electronic Engineering, Anhui Science and Technology University, Fengyang 233100, China
College of Mechanics and Engineering Science, Hohai University, Nanjing 211100, China
School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore

§ Qiuyun Yang, Dehu Li, and Fanfan Shi contributed equally to this work.

Show Author Information

Graphical Abstract

View original image Download original image
A chemical vapor deposition method was developed for synthesizing uniform monolayer tungsten nitride (W2N3) crystals on SiO2/Si substrates, and an effective wet-etch approach was introduced for the visualization of grain boundaries (GBs) using optical microscopy. Electrical measurements demonstrated that GBs of monolayer W2N3 hinder electrical conduction, serving as barriers to transport.

Abstract

Two-dimensional (2D) transition metal nitrides (TMNs) have garnered significant attention in fields such as energy storage and nanoelectronics due to their unique electrical properties, high chemical stability, and excellent mechanical strength. In polycrystalline 2D TMNs films, grain boundaries (GBs) are inevitable structural defects that could play a crucial role in determining the material's properties. Developing rapid optical visualization methods is essential for obtaining large-scale information on the distribution of GBs. However, the rapid visualization of GBs in 2D TMNs, as well as the impact of GBs on the material's electrical properties, has never been previously reported. In this study, we demonstrate the growth of monolayer tungsten nitride crystals on SiO2/Si substrates by chemical vapor deposition (CVD). High-resolution transmission electron microscopy reveals the presence of GBs at the junctions of twisted grains. A wet-etch process utilizing buffered oxide etchant (BOE) enables rapid and effective visualization of these GBs with optical microscopy. By analyzing grains with different twist angles, we find that GBs at specific angles demonstrate increased stability during etching. Electrical measurements revealed that tilted GBs hinder electrical transport, with GBs of a 62° twist angle showing sheet conductance nearly half that within the monolayer grain. This work not only provides insights into GBs in monolayer tungsten nitride but also lays the groundwork for exploring GBs-related properties in other 2D TMNs.

Keywords

two-dimensional (2D) materialsgrain boundarychemical vapor depositionelectrical propertytungsten nitride

Electronic Supplementary Material

Download File(s)
7242_ESM.pdf (790.4 KB)

References

[1]

Wang, H.; Li, J. M.; Li, K.; Lin, Y. P.; Chen, J. M.; Gao, L. J.; Nicolosi, V.; Xiao, X.; Lee, J. M. Transition metal nitrides for electrochemical energy applications. Chem. Soc. Rev. 2021, 50, 1354–1390.

Crossref Google Scholar
[2]

VahidMohammadi, A.; Rosen, J.; Gogotsi, Y. The world of two-dimensional carbides and nitrides (MXenes). Science 2021, 372, eabf1581.

Crossref Google Scholar
[3]

Fan, Y. X.; Li, L.; Zhang, Y.; Zhang, X. T.; Geng, D. C.; Hu, W. P. Recent advances in growth of transition metal carbides and nitrides (MXenes) crystals. Adv. Funct. Mater. 2022, 32, 2111357.

Crossref Google Scholar
[4]

Tang, X.; Guo, X.; Wu, W. J.; Wang, G. X. 2D metal carbides and nitrides (MXenes) as high-performance electrode materials for Lithium-based batteries. Adv. Energy Mater. 2018, 8, 1801897.

Crossref Google Scholar
[5]

Kumar, H.; Frey, N. C.; Dong, L.; Anasori, B.; Gogotsi, Y.; Shenoy, V. B. Tunable magnetism and transport properties in nitride MXenes. ACS Nano 2017, 11, 7648–7655.

Crossref Google Scholar
[6]

Hong, Y. L.; Liu, Z. B.; Wang, L.; Zhou, T. Y.; Ma, W.; Xu, C.; Feng, S.; Chen, L.; Chen, M. L.; Sun, D. M. et al. Chemical vapor deposition of layered two-dimensional MoSi2N4 materials. Science 2020, 369, 670–674.

Crossref Google Scholar
[7]

Wang, H.; Sandoz-Rosado, E. J.; Tsang, S. H.; Lin, J. J.; Zhu, M. M.; Mallick, G.; Liu, Z.; Teo, E. H. T. Elastic properties of 2D ultrathin tungsten nitride crystals grown by chemical vapor deposition. Adv. Funct. Mater. 2019, 29, 1902663.

Crossref Google Scholar
[8]

Xiao, X.; Wang, H.; Bao, W. Z.; Urbankowski, P.; Yang, L.; Yang, Y.; Maleski, K.; Cui, L. F.; Billinge, S. J. L.; Wang, G. X. et al. Two-dimensional arrays of transition metal nitride nanocrystals. Adv. Mater. 2019, 31, 1902393.

Crossref Google Scholar
[9]

Wang, D.; Zhou, C. K.; Filatov, A. S.; Cho, W.; Lagunas, F.; Wang, M. Z.; Vaikuntanathan, S.; Liu, C.; Klie, R. F.; Talapin, D. V. Direct synthesis and chemical vapor deposition of 2D carbide and nitride MXenes. Science 2023, 379, 1242–1247.

Crossref Google Scholar
[10]

Lim, K. R. G.; Handoko, A. D.; Nemani, S. K.; Wyatt, B.; Jiang, H. Y.; Tang, J. W.; Anasori, B.; Seh, Z. W. Rational design of two-dimensional transition metal carbide/nitride (MXene) hybrids and nanocomposites for catalytic energy storage and conversion. ACS Nano 2020, 14, 10834–10864.

Crossref Google Scholar
[11]

Hassan, T.; Kim, J.; Manh, H. N.; Iqbal, A.; Gao, Z. G.; Kim, H.; Hussain, N.; Naqvi, S. M.; Zaman, S.; Narayanasamy, M. et al. Semiconducting properties of delaminated titanium nitride Ti4N3T x MXene with gate-tunable electrical conductivity. ACS Nano 2024, 18, 23477–23488.

Crossref Google Scholar
[12]

Anasori, B.; Lukatskaya, M. R.; Gogotsi, Y. 2D metal carbides and nitrides (MXenes) for energy storage. Nat. Rev. Mater. 2017, 2, 16098.

Crossref Google Scholar
[13]

Becker, J. S.; Gordon, R. G. Diffusion barrier properties of tungsten nitride films grown by atomic layer deposition from bis ( tert-butylimido) bis (dimethylamido) tungsten and ammonia. Appl. Phys. Lett. 2003, 82, 2239–2241.

Crossref Google Scholar
[14]

You, J. Y.; Gu, B.; Su, G.; Feng, Y. P. Two-dimensional topological superconductivity candidate in a van der Waals layered material. Phys. Rev. B 2021, 103, 104503.

Crossref Google Scholar
[15]

Campi, D.; Kumari, S.; Marzari, N. Prediction of phonon-mediated superconductivity with high critical temperature in the two-dimensional topological semimetal W2N3. Nano Lett. 2021, 21, 3435–3442.

Crossref Google Scholar
[16]

Yu, H. M.; Yang, X.; Xiao, X.; Chen, M.; Zhang, Q. H.; Huang, L.; Wu, J. B.; Li, T. Q.; Chen, S. M.; Song, L. et al. Atmospheric-pressure synthesis of 2D nitrogen-rich tungsten nitride. Adv. Mater. 2018, 30, 1805655.

Crossref Google Scholar
[17]

Xiao, X.; Yu, H. M.; Jin, H. Y.; Wu, M. H.; Fang, Y. S.; Sun, J. Y.; Hu, Z. M.; Li, T. Q.; Wu, J. B.; Huang, L. et al. Salt-templated synthesis of 2D metallic MoN and other nitrides. ACS Nano 2017, 11, 2180–2186.

Crossref Google Scholar
[18]

Jin, H. Y.; Gu, Q. F.; Chen, B.; Tang, C.; Zheng, Y.; Zhang, H.; Jaroniec, M.; Qiao, S. Z. Molten salt-directed catalytic synthesis of 2D layered transition-metal nitrides for efficient hydrogen evolution. Chem 2020, 6, 2382–2394.

Crossref Google Scholar
[19]

Zhao, C. B.; Meng, C. X.; Wang, B.; Wang, C.; Li, R. T.; Fu, Q. Vapor–liquid–solid growth of thin and epitaxial transition metal nitride nanosheets for catalysis and energy conversion. ACS Appl. Nano Mater. 2021, 4, 10735–10742.

Crossref Google Scholar
[20]

Guan, H. M.; Li, W. T.; Han, J.; Yi, W. C.; Bai, H.; Kong, Q. H.; Xi, G. C. General molten-salt route to three-dimensional porous transition metal nitrides as sensitive and stable Raman substrates. Nat. Commun. 2021, 12, 1376.

Crossref Google Scholar
[21]

Cao, J.; Li, T. S.; Gao, H. Z.; Lin, Y. X.; Wang, X. Z.; Wang, H. Z.; Palacios, T.; Ling, X. Realization of 2D crystalline metal nitrides via selective atomic substitution. Sci. Adv. 2020, 6, eaax8784.

Crossref Google Scholar
[22]

Chin, H. T.; Wang, D. C.; Gulo, D. P.; Yao, Y. C.; Yeh, H. C.; Muthu, J.; Chen, D. R.; Kao, T. C.; Kalbáč, M.; Lin, P. H. et al. Tungsten nitride (W5N6): An ultraresilient 2D semimetal. Nano Lett. 2024, 24, 67–73.

Crossref Google Scholar
[23]

Chin, H. T.; Wang, D. C.; Wang, H.; Muthu, J.; Khurshid, F.; Chen, D. R.; Hofmann, M.; Chuang, F. C.; Hsieh, Y. P. Confined VLS growth of single-layer 2D tungsten nitrides. ACS Appl. Mater. Interfaces 2024, 16, 1705–1711.

Crossref Google Scholar
[24]

Van Der Zande, A. M.; Huang, P. Y.; Chenet, D. A.; Berkelbach, T. C.; You, Y. M.; Lee, G. H.; Heinz, T. F.; Reichman, D. R.; Muller, D. A.; Hone, J. C. Grains and grain boundaries in highly crystalline monolayer molybdenum disulphide. Nat. Mater. 2013, 12, 554–561.

Crossref Google Scholar
[25]

Yao, W. Q.; Wu, B.; Liu, Y. Q. Growth and grain boundaries in 2D materials. ACS Nano 2020, 14, 9320–9346.

Crossref Google Scholar
[26]

Ly, T. H.; Perello, D. J.; Zhao, J.; Deng, Q. M.; Kim, H.; Han, G. H.; Chae, S. H.; Jeong, H. Y.; Lee, Y. H. Misorientation-angle-dependent electrical transport across molybdenum disulfide grain boundaries. Nat. Commun. 2016, 7, 10426.

Crossref Google Scholar
[27]

Wu, J. Y.; Cao, P. Q.; Zhang, Z. S.; Ning, F. L.; Zheng, S. S.; He, J. Y.; Zhang, Z. L. Grain-size-controlled mechanical properties of polycrystalline monolayer MoS2. Nano Lett. 2018, 18, 1543–1552.

Crossref Google Scholar
[28]

He, Y. M.; Tang, P. Y.; Hu, Z. L.; He, Q. Y.; Zhu, C.; Wang, L. Q.; Zeng, Q. S.; Golani, P.; Gao, G. H.; Fu, W. et al. Engineering grain boundaries at the 2D limit for the hydrogen evolution reaction. Nat. Commun. 2020, 11, 57.

Crossref Google Scholar
[29]

Yu, M. L.; Hu, Z. L.; Zhou, J. Z.; Lu, Y.; Guo, W. L.; Zhang, Z. H. Retrieving grain boundaries in 2D materials. Small 2023, 19, 2205593.

Crossref Google Scholar
[30]

Li, T. T.; Guo, W.; Ma, L.; Li, W. S.; Yu, Z. H.; Han, Z.; Gao, S.; Liu, L.; Fan, D. X.; Wang, Z. X. et al. Epitaxial growth of wafer-scale molybdenum disulfide semiconductor single crystals on sapphire. Nat. Nanotechnol. 2021, 16, 1201–1207.

Crossref Google Scholar
[31]

Yang, P. F.; Liu, F. C.; Li, X.; Hu, J. Y.; Zhou, F.; Zhu, L. J.; Chen, Q.; Gao, P.; Zhang, Y. F. Highly reproducible epitaxial growth of wafer-scale single-crystal monolayer MoS2 on sapphire. Small Methods 2023, 7, 2300165.

Crossref Google Scholar
[32]

Zhao, X. X.; Ji, Y. J.; Chen, J. Y.; Fu, W.; Dan, J. D.; Liu, Y. Y.; Pennycook, S. J.; Zhou, W.; Loh, K. P. Healing of planar defects in 2D materials via grain boundary sliding. Adv. Mater. 2019, 31, 1900237.

Crossref Google Scholar
[33]

Fan, X. G.; Wagner, S.; Schädlich, P.; Speck, F.; Kataria, S.; Haraldsson, T.; Seyller, T.; Lemme, M. C.; Niklaus, F. Direct observation of grain boundaries in graphene through vapor hydrofluoric acid (VHF) exposure. Sci. Adv. 2018, 4, eaar5170.

Crossref Google Scholar
[34]

Duong, D. L.; Han, G. H.; Lee, S. M.; Gunes, F.; Kim, E. S.; Kim, S. T.; Kim, H.; Ta, Q. H.; So, K. P.; Yoon, S. J. et al. Probing graphene grain boundaries with optical microscopy. Nature 2012, 490, 235–239.

Crossref Google Scholar
[35]

Wang, J. H.; Xu, X. Z.; Qiao, R. X.; Liang, J.; Liu, C.; Zheng, B. H.; Liu, L.; Gao, P.; Jiao, Q. Z.; Yu, D. P. et al. Visualizing grain boundaries in monolayer MoSe2 using mild H2O vapor etching. Nano Res. 2018, 11, 4082–4089.

Crossref Google Scholar
[36]

Karvonen, L.; Säynätjoki, A.; Huttunen, M. J.; Autere, A.; Amirsolaimani, B.; Li, S. S.; Norwood, R. A.; Peyghambarian, N.; Lipsanen, H.; Eda, G. et al. Rapid visualization of grain boundaries in monolayer MoS2 by multiphoton microscopy. Nat. Commun. 2017, 8, 15714.

Crossref Google Scholar
[37]

Rong, Y. M.; He, K.; Pacios, M.; Robertson, A. W.; Bhaskaran, H.; Warner, J. H. Controlled preferential oxidation of grain boundaries in monolayer tungsten disulfide for direct optical imaging. ACS Nano 2015, 9, 3695–3703.

Crossref Google Scholar
[38]

Roy, S.; Ansari, K. J.; Jampa, S. S. K.; Vutukuri, P.; Mukherjee, R. Influence of substrate wettability on the morphology of thin polymer films spin-coated on topographically patterned substrates. ACS Appl. Mater. Interfaces 2012, 4, 1887–1896.

Crossref Google Scholar
[39]

Liu, H.; Qi, G. P.; Tang, C. S.; Chen, M. L.; Chen, Y.; Shu, Z. W.; Xiang, H. Y.; Jin, Y. Y.; Wang, S. S.; Li, H. M. et al. Growth of large-area homogeneous monolayer transition-metal disulfides via a molten liquid intermediate process. ACS Appl. Mater. Interfaces 2020, 12, 13174–13181.

Crossref Google Scholar
[40]

Chae, W. H.; Cain, J. D.; Hanson, E. D.; Murthy, A. A.; Dravid, V. P. Substrate-induced strain and charge doping in CVD-grown monolayer MoS2. Appl. Phys. Lett. 2017, 111, 143106.

Crossref Google Scholar
[41]

Sahu, R.; Radhakrishnan, D.; Vishal, B.; Negi, D. S.; Sil, A.; Narayana, C.; Datta, R. Substrate induced tuning of compressive strain and phonon modes in large area MoS2 and WS2 van der Waals epitaxial thin films. J. Cryst. Growth 2017, 470, 51–57.

Crossref Google Scholar
[42]

Zhang, Y.; Zhang, Y. F.; Ji, Q. Q.; Ju, J.; Yuan, H. T.; Shi, J. P.; Gao, T.; Ma, D. L.; Liu, M. X.; Chen, Y. B. et al. Controlled growth of high-quality monolayer WS2 layers on sapphire and imaging its grain boundary. ACS Nano 2013, 7, 8963–8971.

Crossref Google Scholar
[43]

Xie, C. Y.; Jiang, S. L.; Zou, X. L.; Sun, Y. W.; Zhao, L. Y.; Hong, M.; Chen, S. L.; Huan, Y. H.; Shi, J. P.; Zhou, X. B. et al. Space-confined growth of monolayer ReSe2 under a graphene layer on Au foils. Nano Res. 2019, 12, 149–157.

Crossref Google Scholar
[44]

Suleman, M.; Lee, S.; Kim, M.; Nguyen, V. H.; Riaz, M.; Nasir, N.; Kumar, S.; Park, H. M.; Jung, J.; Seo, Y. NaCl-assisted temperature-dependent controllable growth of large-area MoS2 crystals using confined-space CVD. ACS Omega 2022, 7, 30074–30086.

Crossref Google Scholar
[45]

Li, D. W.; Xiao, Z. Y.; Mu, S.; Wang, F.; Liu, Y.; Song, J. F.; Huang, X.; Jiang, L. J.; Xiao, J.; Liu, L. et al. A facile space-confined solid-phase sulfurization strategy for growth of high-quality ultrathin molybdenum disulfide single crystals. Nano Lett. 2018, 18, 2021–2032.

Crossref Google Scholar
[46]

Zhou, S. S.; Gan, L.; Wang, D. L.; Li, H. Q.; Zhai, T. Y. Space-confined vapor deposition synthesis of two dimensional materials. Nano Res. 2018, 11, 2909–2931.

Crossref Google Scholar
[47]

Suzuki, H.; Hashimoto, R.; Misawa, M.; Liu, Y. J.; Kishibuchi, M.; Ishimura, K.; Tsuruta, K.; Miyata, Y.; Hayashi, Y. Surface diffusion-limited growth of large and high-quality monolayer transition metal dichalcogenides in confined space of microreactor. ACS Nano 2022, 16, 11360–11373.

Crossref Google Scholar
[48]

Taborda, J. A. P.; Landázuri, H. R.; Londoño, L. P. V. Correlation between optical, morphological, and compositional properties of aluminum nitride thin films by pulsed laser deposition. IEEE Sens. J. 2016, 16, 359–364.

Crossref Google Scholar
[49]

Jin, H. Y.; Li, L. Q.; Liu, X.; Tang, C.; Xu, W. J.; Chen, S. M.; Song, L.; Zheng, Y.; Qiao, S. Z. Nitrogen vacancies on 2D layered W2N3: A stable and efficient active site for nitrogen reduction reaction. Adv. Mater. 2019, 31, 1902709.

Crossref Google Scholar
[50]

Chiou, B. S.; Lee, J. H. Etching of r. f. magnetron-sputtered indium tin oxide films. J. Mater. Sci. Mater. Electron. 1996, 7, 241–246.

Crossref Google Scholar
[51]

Pinto, R. M. R.; Gund, V.; Calaza, C.; Nagaraja, K. K.; Vinayakumar, K. B. Piezoelectric aluminum nitride thin-films: A review of wet and dry etching techniques. Microelectron. Eng. 2022, 257, 111753.

Crossref Google Scholar
[52]

Ahn, H.; Moon, G.; Jung, H. G.; Deng, B. C.; Yang, D. H.; Yang, S.; Han, C.; Cho, H.; Yeo, Y.; Kim, C. J. et al. Integrated 1D epitaxial mirror twin boundaries for ultrascaled 2D MoS2 field-effect transistors. Nat. Nanotechnol. 2024, 19, 955–961.

Crossref Google Scholar
[53]

Su, L. Q.; Zhang, Y.; Yu, Y. F.; Cao, L. Y. Dependence of coupling of quasi 2-D MoS2 with substrates on substrate types, probed by temperature dependent Raman scattering. Nanoscale 2014, 6, 4920–4927.

Crossref Google Scholar
[54]

Su, L. Q.; Yu, Y. F.; Cao, L. Y.; Zhang, Y. Effects of substrate type and material-substrate bonding on high-temperature behavior of monolayer WS2. Nano Res. 2015, 8, 2686–2697.

Crossref Google Scholar
[55]

Anasori, B.; Shi, C. Y.; Moon, E. J.; Xie, Y.; Voigt, C. A.; Kent, P. R. C.; May, S. J.; Billinge, S. J. L.; Barsoum, M. W.; Gogotsi, Y. Control of electronic properties of 2D carbides (MXenes) by manipulating their transition metal layers. Nanoscale Horiz. 2016, 1, 227–234.

Crossref Google Scholar
[56]

Liu, Y. Y.; Stradins, P.; Wei, S. H. Air passivation of chalcogen vacancies in two-dimensional semiconductors. Angew. Chem. 2016, 128, 977–980.

Crossref Google Scholar
[57]

Grünleitner, T.; Henning, A.; Bissolo, M.; Zengerle, M.; Gregoratti, L.; Amati, M.; Zeller, P.; Eichhorn, J.; Stier, A. V.; Holleitner, A. W. et al. Real-time investigation of sulfur vacancy generation and passivation in monolayer molybdenum disulfide via in situ X-ray photoelectron spectromicroscopy. ACS Nano 2022, 16, 20364–20375.

Crossref Google Scholar
[58]

Bussolotti, F.; Kawai, H.; Maddumapatabandi, T. D.; Fu, W.; Khoo, K. H.; Goh, K. E. J. Role of S-vacancy concentration in air oxidation of WS2 single crystals. ACS Nano 2024, 18, 8706–8717.

Crossref Google Scholar
Nano Research
Volume 18 Issue 3,
March 2025
Article number: 94907242
DOI: 10.26599/NR.2025.94907242
Cite this article:
Yang Q, Li D, Shi F, et al. Synthesis of monolayer tungsten nitride: Rapid optical visualization and electrical impact of grain boundaries. Nano Research, 2025, 18(3): 94907242. https://doi.org/10.26599/NR.2025.94907242
Topics:
Film growth
Metrics & Citations  
Article History
Copyright
Rights and Permissions
Return